The present invention relates to a wear resistant overlay for use in a decorative laminate and flooring and to laminates and flooring prepared therefrom. Decorative laminates have been conventionally made by stacking a plurality of layers of paper impregnated with synthetic thermosetting resins. Normally, the assembly consists of a plurality (for example, three to eight) core sheets made from phenolic resin impregnated Kraft paper, above which lies a decor sheet, usually a print or solid color, impregnated with melamine resin. An overlay sheet is often provided on top of the decor sheet which, in the laminate, is made to be as transparent as possible and which provides protection for the decor sheet.
The overlay sheet can be formed in a number of different ways. In one, the overlay is a sheet of cellulose fibers having a very low basis weight which carries therein and thereon abrasion resistant particles. Conventionally, the cellulose fibers are deposited on the papermachine wire from a first headbox and overcoated with a slurry of mineral particles which are deposited from a secondary headbox. The slurry of mineral particles cascades over and through the cellulose fibers and causes many of the mineral particles to become embedded in the overlay where they are not as effective in preventing abrasion. Also much of the mineral particles is washed to the floor of the papermachine. Thus, the conventional practice of depositing mineral particles from a secondary headbox is terribly inefficient in terms of the usage of the mineral particles.
One method for more efficiently depositing the mineral particles involves use of a slot orifice coater such as a curtain coater instead of a secondary headbox as described in U.S. Pat. No. 5,820,937.